1. Field of the Invention
The present invention relates to a recording method for recording information on one of a plurality of information tracks provided in parallel with each other on an information recording medium while performing a tracking servo operation. The present invention also relates to a recording apparatus for performing the above recording method.
2. Related Background Art
Conventionally, as information recording mediums on which information is recorded or from which information is read out, various types, such as a disc=shaped one, card-shaped one, tape-shaped one or the like, are already known. In addition, recently, a recording method for recording and/or reading out the information with respect to such a recording medium by applying a light beam condensed as a light spot to the recording medium has been noted with success because the recording density has been considerably increased.
Here, such a recording method will be explained, taking the case of a card-shaped optical recording medium (referred to as "optical card" hereinafter) as an example.
FIG. 1 is a schematic plan view of the optical card, and FIG. 2 shows a portion of the optical card in an enlarged scale.
In FIG. 1, reference numeral 1 denotes an optical card, numeral 2 denotes an information track, and numeral 3 denotes a home position. On the optical card 1, information is recorded as a row of optically detectable recording bits (information track) by scanning the card 1 by means of a light beam which is modulated in accordance with the information to be recorded and which is condensed or focused as a minute light spot. In this case, in order to correctly record and/or reproduce the information without trouble such as crossing of the information tracks 2, it is required that a position of the light beam (spot) applied to the card be controlled in a direction perpendicular to a scanning direction (automatic tracking referred to as "AT" hereinafter). Further, it is also required that the light spot, be controlled in a direction perpendicular to a plane of the optical card (automatic focusing referred to as "AF" hereinafter) in order that the minute light spot be stably applied to the card regardless of bent or distortion of the card and/or mechanical errors. As shown in FIG. 2, between two adjacent information tracks 2 (2.sub.1, 2.sub.2, ...), there are provided tracking tracks 5 (5.sub.1, 5.sub.2, ...), for effecting the abovementioned AT.
Next, the recording process for recording information on the optical card will be explained.
In FIG. 1, at first, the light spot is positioned in the home position 3. Next, the light spot is shifted in a direction D (FIG. 1) to find an information track 2.sub.n to be recorded; then, the light spot scans, the track 2.sub.n in a direction F, thereby recording or reproducing the information with respect to the track 2.sub.n. A track number has also been recorded on each of the information tracks. Thus, it is possible to find the information being now recorded, by reproducing the information regarding the track numbers. The recording of information is effected in postscript fashion in order of the information tracks 2.sub.1, 2.sub.2, ... 2.sub.n.
When there are flaws or scratches on the optical card or when dirt and/or dust sticks to the optical card, as well as when a defect portion exists on a recording layer of the optical card, in some cases, recording of information cannot be correctly effected. In order to avoid such demerit, the Japanese Patent Laid-Open Application No. 240408/1986 (corresponding to U.S. Ser. No. 850,830) proposes a method for verifying if information has been correctly recorded by reproducing the information immediately after this information is recorded. In this method, when an error is detected, the same information is recorded on a next track.
However, when the defect portion and the like on the optical card is so large as to stride a plurality of the tracks, abnormality of the tracking servo operation (phenomenon that the light spot cannot correctly trace the information track due to AT out of track) is generated, as well as mechanical errors are generated. In this case, since in the above proposed method the re-recording operations must be successively repeated, there arises a problem that it takes a long time for restoring a normal recording condition.